The FDA approved soy protein isolate at a daily intake of 25g despite its own safety committee recommending a maximum of 150mg per day.

Verified by Lenz · Apr 14, 2026

The Short Version

The central allegation — that an FDA safety committee recommended a 150mg/day maximum for soy protein isolate — is not supported by any FDA document, Federal Register entry, or peer-reviewed source in the evidentiary record. While the FDA did authorize a heart-health label claim tied to 25g/day of soy protein, and two individual FDA scientists raised concerns about isoflavone-related effects, no formal committee ever set a 150mg/day protein limit. The claim conflates milligram-range isoflavone discussions with gram-range protein intake and mischaracterizes individual dissent as an official committee recommendation.

Caveats

No FDA safety committee recommendation of a 150mg/day maximum for soy protein isolate exists in any authoritative source reviewed; this figure likely conflates isoflavone intake discussions with soy protein intake.
The claim misrepresents two individual FDA scientists' objections (Drs. Doerge and Sheehan) as an official 'safety committee' recommendation — these were dissenting opinions, not a formal committee finding.
The FDA's 25g/day figure is a qualifying threshold for a specific heart-health label claim under 21 CFR 101.82, not a general 'approval' of soy protein isolate consumption at that level.

The Receipts

Federal Register/Vol. 64, No. 206/Tuesday, October 26, 1999/Rules ...
Federal RegisterOct 26, 1999
Health claims: Soy protein and risk of coronary heart disease (CHD).
eCFR
Food Labeling: Health Claims; Soy Protein and Coronary Heart Disease
Federal RegisterOct 31, 2017
soy protein, isolate - cfsanappsexternal.fda.gov
FDA
Food Labeling: Health Claims; Soy Protein and Coronary Heart Disease - Federal Register
Federal RegisterOct 31, 2017
The Dilemma With the Soy Protein Health Claim - PMC - NIH
PubMed Central - NIHAug 20, 2019
Soy and Health Update: Evaluation of the Clinical and ... - PMC
PMCNov 9, 2016
The health effects of soy: A reference guide for health professionals
PubMed CentralAug 15, 2022
A Meta-Analysis of 46 Studies Identified by the FDA Demonstrates...
PubMed Central / NIHJun 14, 2019
Soy: A Complete Source of Protein | AAFP
AAFPJan 1, 2009

+ 8 more sources — see the full list on Lenz

Filed Under

Soy Protein IsolateUnited States Food and Drug Administration

The FDA approved soy protein isolate at a daily intake of 25g despite its own safety committee recommending a maximum of 150mg per day.

The Short Version

Caveats

The Receipts

Filed Under

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